The planned “pause” in Arctic drilling will give Shell and its contractors time to repair two drilling rigs and stand up an emergency oil spill containment system, while the company continues scientific research in the region.

The move also allows the Obama administration to avoid a politically charged decision about whether to allow the company to resume drilling two wells in the Beaufort and Chukchi seas this summer. The Interior Department last month launched a a high-level review of the 2012 Arctic drilling program, including the challenges Shell faced moving ships and people to its remote offshore wells.

Shell’s move underscores the financial risks and other perils of Arctic drilling, even as the lure of untapped crude inspires a new oil rush at the top of the globe. And though Shell stressed Wednesday that it remained committed to Arctic drilling, the delay is a major setback for the company that has poured some $5 billion into leading the effort in U.S. waters.

“We’ve made progress in Alaska, but this is a long-term program that we are pursuing in a safe and measured way,” said Shell Oil President Marvin Odum. “Our decision to pause in 2013 will give us time to ensure the readiness of all our equipment and people.”

“Shell remains committed to building an Arctic exploration program that provides confidence to stakeholders and regulators and meets the high standards the company applies to its operations around the world,” Odum said in a statement. “We continue to believe that a measured and responsible pace, especially in the exploration phase, fits best in this remote area.”

Company spokesman Curtis Smith said Shell could seek to resume Arctic exploration next year.

“The results of ongoing reviews will be part of our planning for future programs, including a possible program in 2014,” he said. “Our future exploration plans offshore Alaska will depend on a number of factors, including the readiness of our rigs and the confidence that lessons from 2012 will be fully incorporated.”

Shell was forced to constrain its 2012 operations to “top-hole” drilling of the initial 1,500 feet of its Arctic wells, after its unique oil spill containment system was damaged during a deployment drill and could not get to the area in time.

There were other mishaps, too: The Noble Discoverer briefly drifted out of control near Dutch Harbor last July. A fire broke out in the rig stack on the Discoverer while it was in Dutch Harbor last November, weeks before the vessel had propulsion problems pulling into Seward. And the Environmental Protection Agency said Shell violated the terms of air pollution permits governing its operations by releasing too many nitrogen oxide emissions from its drilling rigs and support vessels.

The most high-profile setback came on Dec. 31, when Shell’s Kulluk rig collided with the rocky shore of Sitkalidak Island near Kodiak City, Alaska, following a five-day battle to tow the unpropelled vessel to safe harbor amid 70-mph winds and waves that climbed four-stories high. The rig was later pulled to sheltered Kiliuda Bay, and on Tuesday, it began a 10-day trek to Dutch Harbor for further examination, after which it will be shipped to a yet-to-be-determined Asian port for repairs.

Environmentalists applauded Shell’s decision and called on the Obama administration to use the extra time to either halt Arctic exploration altogether or impose new requirements on the work.

“Given the disastrous 2012 season, our government agencies must take advantage of this opportunity to reassess the way decisions are made about our ocean resources and to reconsider the commitment to explore for oil in the Arctic Ocean,” said Michael LeVine, Pacific senior counsel for Oceana. “Science, planning, and preparedness — not luck — should be our guides in the future. ”

Marilyn Heiman, the director of Pew Environment Group’s Arctic Program, said Shell’s decision shows the company “is realizing that they need to take a more careful approach to ensure they don’t put the Arctic’s people and marine life at risk.”

But that should be followed by “world-class industry standards” designed to protect “important ecological and cultural areas” in the Arctic, she said.

Shell’s struggles to tap Arctic crude raise questions about the financial costs of the pursuit, especially as the U.S. produces more oil from dense shale rock formations onshore, said Lois Epstein, The Wilderness Society’s Arctic Program director.

“The big, long-term question is whether Arctic Ocean drilling — which always will be among the riskiest and most costly oil drilling in the world — will pencil out as shale oil and deep-water production increases worldwide,” Epstein said.

Shell has taken the lead in pursuing Arctic drilling in U.S. waters, decades after the last sustained drilling in the region. ConocoPhillips and Statoil also hold drilling leases in the U.S. Arctic.

ExxonMobil, Cairn Energy and Gazprom are all pursuing ventures in foreign Arctic waters.

Geologists estimate 412 billion barrels of oil equivalent are lurking in the Arctic, about a quarter of the world’s undiscovered conventional crude and natural gas resources.

Beyond the billions that Shell has sunk into buying its Arctic drilling leases and renovating rigs, the company has built a broad infrastructure in Wainwright and Barrow, Alaska to support the work. For instance, Shell has installed crew camps in Wainwright, Barrow and Deadhorse, Alaska and built a new airplane hanger in Barrow. It is leasing a hanger in Deadhorse and has stashed oil spill response equipment along the Alaska coast.

It also spent hundreds of millions of dollars building its emergency capping and containment systems and poured another $350 million into building two ships designed for the Beaufort and Chukchi seas.

Rear Adm. Thomas Ostebo, incident management team commander, observes the Shell drilling rig Kulluk aground during an overflight off a small island near Kodiak Island

Rear Adm. Thomas Ostebo, incident management team commander, observes the Shell drilling rig Kulluk aground during an overflight off a small island near Kodiak Island

Photo: (AP Photo/U.S. Coast Guard, Sara Francis)

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Eighteen crew members of the mobile drilling unit Kulluk arrive at Air Station Kodiak after being airlifted by a Coast Guard helicopter from a vessel 80 miles southwest of Kodiak, Alaska on Saturday, Dec. 29, 2012. less

Eighteen crew members of the mobile drilling unit Kulluk arrive at Air Station Kodiak after being airlifted by a Coast Guard helicopter from a vessel 80 miles southwest of Kodiak, Alaska on Saturday, Dec. 29, ... more

Waves crash over the mobile offshore drilling unit Kulluk where it sits aground on the southeast side of Sitkalidak Island, Alaska, Jan. 1, 2013. A Unified Command, consisting of the Coast Guard, federal, state, local and tribal partners and industry representatives was established in response to the grounding. U.S. Coast Guard photo by Petty Officer 3rd Class Jonathan Klingenberg. less

Waves crash over the mobile offshore drilling unit Kulluk where it sits aground on the southeast side of Sitkalidak Island, Alaska, Jan. 1, 2013. A Unified Command, consisting of the Coast Guard, federal, ... more

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A salvage team moves an emergency towing system across the deck of petroleum drilling ship Kulluk.

A salvage team moves an emergency towing system across the deck of petroleum drilling ship Kulluk.

Photo: (AP Photo/U.S. Coast Guard)

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The Crowley Marine tugboat Alert ties up at Pier 2 in Kodiak, Alaska. The Alert was one of the tugs summoned to Kodiak in an effort to keep the drilling rig Kulluk from running aground.

The Crowley Marine tugboat Alert ties up at Pier 2 in Kodiak, Alaska. The Alert was one of the tugs summoned to Kodiak in an effort to keep the drilling rig Kulluk from running aground.

Photo: (AP Photo/Kodiak Daily Mirror, James Brooks)

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The tugs Aiviq and Nanuq tow tandem tow the mobile driling unit Kulluk 116 miles southwest of Kodiak City, Alaska. The tugs were attempting to tow the Kulluk to a sheltered area but weather conditions, including 29 mph winds and 20-foot seas, have deterred them. less

The tugs Aiviq and Nanuq tow tandem tow the mobile driling unit Kulluk 116 miles southwest of Kodiak City, Alaska. The tugs were attempting to tow the Kulluk to a sheltered area but weather conditions, ... more